1. Field of the Invention
The present invention relates to an image forming apparatus. More particularly, the present invention relates to a developer cartridge for a liquid-type image forming apparatus and a method for disposing of the same.
2. Description of the Related Art
Generally, image forming apparatuses are divided into monochromatic image forming apparatuses and color image forming apparatuses. Monochromatic image forming apparatuses implement images in black and white by using only a one-color developer. Color image forming apparatuses implement colorful images by using developers of various colors, which are typically magenta, cyan, yellow and black.
An electrophotographic image forming apparatus forms an electrostatic latent image on an organic photoconductor, charged by a charging unit, to have a predetermined potential by a laser beam emitted from a laser scanning unit. The electrostatic latent image is developed with a developer and transferred into a visible image on paper. In a color image forming apparatus, an organic photoconductor of each color is developed with developers of each color. Then, the developed images are overlapped and transferred to an intermediate transfer medium, such as an intermediate transfer belt (ITB). A color image obtained by overlapping images of each color on the intermediate transfer medium is transferred onto printing paper. The printing paper containing the color image goes through a series of fixing processes and is discharged out of the image forming apparatus.
FIG. 1 shows a structure of a conventional color image forming apparatus that performs a two-step transfer operation by using an intermediate transfer belt. Referring to FIG. 1, the color image forming apparatus comprises an intermediate transfer belt 10, a supporting roller 11, first transfer (T1) rollers 12, 13, 14 and 15 for each color, organic photoconductors 16, 17, 18 and 19 for each color, a second transfer (T2) roller 20, and a belt driving roller 21.
On the organic photoconductors 16, 17, 18 and 19 of each color, developers of black (K), cyan (C), magenta (M), and yellow (Y) colors are attached to an electrostatic latent image area through a developing process. For each color, the T1 rollers 12, 13, 14 and 15 are set up to correspond to the organic photoconductors 16, 17, 18 and 19 with the intermediate transfer belt 10 between them. Accordingly, the developers attached to the surface of the organic photoconductors 16, 17, 18 and 19 are transferred onto the surface of the intermediate transfer belt 10 primarily by transfer operations of the T1 rollers 12, 13, 14 and 15. Herein, the T1 rollers 12, 13, 14 and 15 are placed with a predetermined interval so that the developers of each color transferred from the organic photoconductors 16, 17, 18 and 19 onto the intermediate transfer belt 10 are overlapped in the same location. The developers are primarily overlapped on the intermediate transfer belt 10 to thereby form one complete color image. Subsequently, the color image on the intermediate transfer belt 10 goes through a secondary transfer operation between the T2 transfer roller 20 and the belt driving roller 21. The color image is then transferred onto a printing medium 23.
Meanwhile, the image forming apparatus includes developing units 26, 27, 28 and 29 for each color in order to develop the organic photoconductors 16, 17, 18 and 19 with the developers of each color. Each of the developing units 26, 27, 28 and 29 is provided with a developer from each of developer cartridges 36, 37, 38 and 39 for each color by using a pump (P). Waste developer, including a liquid carrier remaining after being used in the developing units 26, 27, 28 and 29, is collected into the developer cartridges.
Meanwhile, the developer cartridges 36, 37, 38 and 39 of each color are connected with the developing units 26, 27, 28 and 29 when they are set up in the image forming apparatus to thereby supply the developers. The developer cartridges 36, 37, 38 and 39 should be replaced with new ones when the developers accommodated in the developer cartridges are all consumed. However, when the developer cartridges 36, 37, 38 and 39 are separated out of the image forming apparatus for disposal, the collected waste developer, including the liquid carrier, remains inside. Therefore, when the developer cartridges 36, 37, 38 and 39 are separated, waste developer leakage may be a problem.
Accordingly, there is a need for an improved image forming apparatus having a developer cartridge to prevent leakage of waste developer.